Alkyd resin



Patented July 28, 1953 ALKYD RESIN Carl J. Opp and Raymond E. Werner,Cincinnati, Ohio, assignors to Interchemical Corporation, New York, N.Y., a corporation of Ohio No Drawing. Application July 12, 1951, SerialNo. 236,480

4 Claims.

1 This invention relates to the preparation of modified alkyd resins.

Modified alkyd resins are among the most versatile of all resin typesand many have found great commercial utility. Among the most use- 111 ofthe modified alkyds, are the drying oilmodified alkyds, the non-dryingoil-modified alkyds and rosin acids modified alkyds. Incorporation of 25per cent or more of such oils or the fatty acids from such oils orrosin, into alkyds overcomes the inherent brittleness of the pure alkydand gives a resin suitable for use in protective and decorativefinishes. One such use for oil-modified alkyds or rosin modified alkydsis in blends with Beetle type resins, such as ureaformaldehyde andmelamine formaldehyde resins for use as baking enamels. Advantagesobtained are increased hardness and mar resistance and the finish may bebaked at high temperatures without danger of discoloration.

The present invention has as one of its main objects th production of anovel type of modified alkyd resin particularly characterized by containing relatively large amounts of copolymerized methyl methacrylate orstyrene. These modified alkyds are particularly characterized by beingreadily compatible with urea-formaldehyde and melamine-formaldehyderesins. This property of the novel resins makes them particularly usefulin the preparation of protective and decorative coatings.

The modified alkyds of the present invention are prepared by firstheating a mixture of styrene monomer or methyl methacrylate monomer withthe desired proportion of rosin, in the presence of a peroxide catalystand an alkyl mercaptan having at least four carbon atoms according tothe procedure covered by our copending application, Serial Number713,932, filed December 4, 1946, to form a methyl methacrylate orstyrene rosin copolymer.

The copolymer is then converted to an alkyd resin by reacting it withpolyhydric alcohol, e. g. glycerol or pentaerythritol, andpolycarboxylic acid; e. g. phthalic acid, maleic acid, sebasic acid andPetrex acid (condensation product of maleic anhydride and terpene) Itwill be obvious to those skilled in the art of preparing modified alkydsthat the particular procedure used to prepare alkyds according to ourinvention may vary from one preparation to another and will depend forthe most part on the particular starting materials employed.

We know of no limitations on the ratios of methyl methacrylate copolymeror styrene copolymer and polyhydric alcohol and polybasiccarboxylic acidwhich may be reacted to give the novel products of our invention. Hence,the ratios of the various reactants used will be governed by theproperties which will be desired in the alkyd. To those experienced inthe art of cooking alkyds resin it will be obvious that our process canbe used to prepare alkyd resins having a wide variety of properties. Forexample, large ratios of a :40 methyl methacrylate-rosin copolymer wouldtend to give an alkyd having more pronounced properties resulting frommethyl methacrylate copolymer than an alkyd containing small ratios ofthe methyl methacrylate copolymer.

The alkyd portion of our resins may be formed from any of the commonlyused polyhydric alcohols and polybasic carboxylic acids. Polyhydricalcohols, such as ethylene glycol, diethylene glycol, glycerol orpentaerythritol are preferred because they are more readily availablethan other polyhydroxy alcohols, such as mannitol, sorbitol and thelike. Similarly, such readily available polybasic carboxylic acids asphthalic, citric, maleic, fumaric, sebasic, azelaic, adipic, itaconicand Petrex acids (Hercules Powder Co.) are prepared to the less readilyavailable acids.

The invention will be more fully understood by reference to thefollowing examples in which the parts are by weight.

Example I.-30:70 styrene rosin copolymer Parts Rosin 1050 Styrene 4'50t-Butyl mercaptan 22 t-Butyl hydroperoxide 18 Example II .-40:60 styrenerosin copolymer Parts Rosin 600 Styrene 400 Amyl mercaptan 20 t-Butylhydroperoxide 15 The ingredients were reacted in a manner similar tothat of Example I to obtain a copolymer having a melting point of 50 C.and an acid number of 95.

Example III .50.'50 styrene rosin copolymer Parts Rosin 750 Styrene 750Amyl mercaptan 38 t-Butyl peroxide 30 The copolymer was preparedaccording to procedure of Example I to give a clear, hard, brittle,light, colored resin having a melting point of 55 C. and an acid numberof 81.

Example IV.40:60 methyl methacrylate rosin copolymer Parts Rosin 900Methyl methacrylate 600 t-Butyl mercaptan 38 t-Butyl hydroperoxide 30The rosin was heated in a flask at 350 F. under reflux and agitationwhile the other three ingredients were added below the liquid surface ofthe rosin at such a rate as to maintain a steady reflux. The temperatureis then gradually increased to 450 to 500 F. to complete thecopolymerization and obtain a product having an acid number of 96 to 98.The copolymer was clear when hot, but had a milky appearance when cooledto room temperature. Similar copolymers are obtained from 30:70 and50:50 ratios of methyl methacrylate to rosin.

All of the above copolymers can be used in making modified alkyd resinsin accordance with the invention. The modified alkyds are compatiblewith melamine-formaldehyde and ureaformaldehyde resin. The followingexamples are typical of alkyd resins made from the above copolymers.

Example V Parts 40:60 styrene rosin copolymer (Example 11) 900 Glycerol240 Phthalic anhydride 360 The above ingredients were reacted by heatingat 450 F. in carbon dioxide atmosphere until an acid number of 12 orless was obtained and then cooled to 400 1". and reduced to 60% totalnonvolatile components with xylol. The alkyd contains 25% styrene and36% rosin acids.

' Example VI 7 7 Parts 40:60 methyl methacrylate rosin copolymer(Example IV) .626 Glycerol 174 Phthalic anhydride 200 The procedure wassimilar to that of Example V to give a resin having a viscosity of Q-R(Gardner) when reduced to 60% total non-volatiles 4 with a 3 :1 mixtureof xylol and Cellosolve (monoethyl ether of ethylene glycol). This resincontains 25% methyl methacrylate modification, 38% of rosin acids, andhas a COOH to OH ratio of 5:75.

Similar alkyds are obtained using copolymers containing other ratios ofstyrene or methyl methacrylate to rosin. In order that the styrene ormethyl methacrylate show appreciable effect on the properties of thealkyd, the copolymer should contain at least about 10% of the styrene ormethyl methacrylate. Similarly, rosin should constitute at least about10% of the copolymer.

This application is a continuation-in-part of our copending applicationSerial No. 713,932, filed December 4, 1946, now Patent No. 2,560,592.

We claim:

1. An alkyd resin comprising the reaction product of a polybasiccarboxylic acid, a polyhydric alcohol, and the copolymerization productof rosin with a monomer of the class consisting of styrene and methylmethacrylate in the presence of a peroxide catalyst and an alkylmercaptan having at least four carbon atoms, said alkyd resin beingcompatible with urea-form aldehyde and melamine-formaldehyde resins.

2. An alkyd resin comprising the reaction product or a polybasiccarboxylic acid, a polyhydric alcohol, and the copolymerization productof rosin with styrene in the presence of a peroxide catalyst and analkyl mercaptan having at least four carbon atoms, said alkyd resinbeing compatible with urea-formaldehyde and melamineformaldehyde resins.

3. An alkyd resin comprising the reaction product of a polybasiccarboxylic acid, a polyhydric alcohol, and the copolymerization productof rosin with methyl methacrylate in the pres-- ence of a peroxidecatalyst and an alkyl mercaptan having at least four carbon atoms, saidalkyd resin being compatible with urea-formaldehyde andmelamine-formaldehyde resins.

4. A method for preparing an alkyd resin comprising heating atesterification temperatures, a polybasic carboxylic acid, a polyhydricalcohol, and the copolymerization product of rosin with a member of theclass consisting of methyl methacrylate and styrene in the presence of aperoxide catalyst and an alkyl mercaptan having at least four carbonatoms, such alkyd being compatible with urea-formaldehyde andmelamine-formaldehyde resins.

CARL J. OPP. RAYMOND E. WERNER.

References Cited in the file of this patent UNITED STATES PATENTS Number

1. AN ALKYD RESIN COMPRISING THE REACTION PRODUCT OF A POLYBASICCARBOXYLIC ACID, A POLYHYDRIC ALCOHOL, AND THE COPOLYMERIZATION PRODUCTOF ROSIN WITH A MONOMER OF THE CLASS CONSISTING OF STYRENE AND METHYLMETHACRYLATE IN THE PRESENCE OF A PEROXIDE CATALYST AND AN ALKYLMERCAPTAN HAVING AT LEAST FOUR CARBON ATOMS, SAID ALKYD RESIN BEINGCOMPATIBLE WITH UREA-FORMALDEHYDE AND MELAMINE-FORMALDEHYDES RESINS.